Automatic firearm



May 21, 1929, J. DESTREE AUTOMATIC FIREARM Filed April 1s, 1927 Eva-s172017 JD ssh-vs f Patented May 21, 1929.

UNITED STATES DESTRE, OF BRUSSELS, BELGIUM.

AUTOMATIC FIREARM.

Application 1ed April 13, 1927, Serial No. 183,541, and in Belgium July 10, 1926.

. The present invention relates to tire arm i of the kind in which all the automatic operations are obtained by means of one or' lmore springs which are stressed through the medium'of a piston upon which the gases produced by the combustion of the powder are made to act; l

Devices of this kind are known in which ,the gases are made.' to act upon the said 'Y Ypiston in a cylinderilbyV being led through a Vigas port.` Although the aperture adopted'is v always small thev piston and the springs it fcontrols are shattered by the violent action l `of the gases; These devices have the furthery 15. disadvantage of damping the return stroke of the piston on'account of the small size of y the gas outlet orifice. Moreover, this orifice becomes rapidly choked up by thek deposits produced in it. 1

It has been proposed to brake the piston Vby the gases which expel the projectile. In the known devices of this kind the braking gases are forced against the braking mechaf nism from a main part of the cylinder with r the result that the motive gases are considerably spent. This admission of the braking gases is further' effected at the end of the stroke of the piston in a manner that moves it at aiy very great speed during the greater` part of its stroke promoting damage to the parts operating in conjunction therewith. The object of the present invention is to overcome these disadvantages while preventing the fracture' of the parts. y l :y lVithr this ob'ect in view, the invention .A consistsin leading in the gases through a A fairly large orifice which allows the gases to `pass away rapidly when the piston, makes its return stroke, the movement ofthe piston beingv gradually restrained during its for* f ward stroke beforefit reaches the end ofits v stroke. 4

Due to this, the braking gases are taken s directly from the barrel and are admitted to act from the moment when the piston has notrtravelled more than a small part of its stroke under the action of the motive gases. Furthermore, the admission of the motive gases and the braking gas is effected through )passages which are of relatively large secf tion. This result may be obtained by forming, on-the opposite side of the gas intake from therside where the breech is located, a second gas inlet formed by a fairly `large orifice and by malng the gases act upon the other face of the piston ask soon as the latter has begun its forward stroke.

The gases may also be made to act upon the opposite face of the piston to the one which the driving action is produced by forming at a determined point along the cylinder in which the piston moves, a recess permitting the Acompressed gases to pass rfound the pistonand act upon the-opposite ace.

- The single Agas inlet necessary in this case may be formed by an orifice inthe wall of the barrel of the fire arm or' in a sleeve dis posed at the outlet fromthe barrel and having adiameter a little larger than that of the projectile.

The accompanying drawings illustrate diagrammatically by way of example, somek forms of the invention.

F 1g. 1y 1s a perspectivev1ew, partly in section, of a deviceaccordmgto the invention with two gas inlets of fairly large dimenslons, one.of these inlets leading the compressed gasesl fromthe explosion upon the piston and the other admitting the gas exerting a braking action upon the piston.

Figs. 2 and 3 illustrate forms of the device wherein a single gas inlet Voffairly large dimensions is provided, the gas inlet being formed in the ir'st case in the wall of the gun barrel and in the, second case in that of a socket orsleeve of larger diameter than the gun barrel, so as to make'the compressed gases undergo al preliminary expansion.

',Fig. 1 shows a gun -barrelvin'the wall of which has been pierced a first fairly large aperture 2 leading the gas to one end of a cylinder 3 containing a piston 4 which compresses a spring 5 when it is displaced in the direction of the arrow 6. When this spring expands it acts upon a lever 7 which is constantly pressed upwardsby a spring 8. Under these conditions the end 9 of the lever 7 presses upon a stop 10 of the screw plate mechanism controlling the various' automatic operations'. The stop 10 is displaced towards the end of the recoil ofthe piston 4, until the moment when a cam 11 makes the lever 7 pivot downwards to press upon the spring 8. The other end of the cylinder' also com municates through a fairly large aperture with the gun barrel l. When the projectile is driven out of the gun barrel the gases are first of all admitted on to the right hand face of the piston l in Figure 1 through the aperture 2. But before the piston l has reached the end of vits stroke the projectile Will have passed beyond the aperture 12 and the gases are admitted on to the other' face of the piston, thus exerting a braking action on the movement of the latter inthe direction of the arrow 6 and preventing the fracture of the piston and the members which Y are attached to it, in spite of the high pressure action in the cylinder.

Inorder to reduce the braking action in case of need, asmall port allowingthe braking y.gases to escape'directly-into thev atmosphere may be formed in the endlB-o the cylinderv 3 near the second gas inlet or in this inlet itself. i

.The device which 'has been described pre# vents the choking up of the gas inlets as Well'as the exertion of a braking-action onv the piston upon its return stroke when the pressure of the gases in the fire arm vfalls after the projectile has passed out. Y

The same effect may be obtained in the device shown in Fig. 2 in Whichfthe gases are only admitted into the cylinder 3 through one single gas` inlet- 2 but in which the cyl'- inder 3, comprises, rat a `determined pointV along the stroke of the piston .4, a recess 14 permitting the gases to act betweenthe end 13 of the cylinder and the face'o the pistonV 4 which is opposite this end.

If it is considered'necessary, the gas inlet 2 maybe formed in a sleeve or socket 15 l after the cylinder 3, Which holes Will besituated in' front of the recess V14: so as to be uncovered piston 4 hasmoved aL `veiyvshort distance.

VVhat I claim is:

lixed barrel, a cylinder, a plunger in ythis cylinder acting on springs, a yconnection between th'ese springs and the breechfor operating thevarious automatic operations of the breech afterV the springs have Vbeen stressed by the plunger, means for ,admit ting directly the gases from' thepbarreljon VIn testimony whereof of the.l gases.v

2. An automatic fire arm comprising a fixed barrel, a cylinder, a plunger in the cylinder actingpon springs, a connection between these springs-'and the' breech vfor operating the'variousr automatic operations of the breech after the springs vhave' been ,Y stressed by the plunger, meansifor admitting directlythe gases from the barrelonone face of the plunger, means for admit-ting directly and subsequentlyl the gases fron'rthe barrel on the opposite face of the plunger as soon as this plunger'has travelled a smalll Pm fits Stlok'und'er the action of the. j-' gases, thesetwo `means presenting fairly large sectionsfor the'passage of the gases.

3. In an automatic firearm, inj'combination, a'gun barrel having the bore provided- With spaced outlet Vportsr "adapted y'to be lsuccessively'uncovered by the passage of a; projectile, aV pressure cylinder in communication withv said ports,V anda spring tensioned adapted to beymoved in one'directionf by the gasesv entering the cylinder through one of the said ports andbei-ng adapted Valso to be almost instantly retarded in its movement by the gases subsequently admitted through theother port. 'f

- L In an automatic `fire arm, in combination, a gun barrel` having the bore provided With spaced outlet ports adapted to besuccessively uncoveredv by the passage of a `pro- ]ect1le,va pressure cylinder 1nV communication With said ports, andasprmg tensioned vplunger operating Within the cylinder'and Vbetween the said ports, `said plunger'being plunger operatingl WithinV the cylinder andV ,A

Vbetween the said ports, said plunger being A Vadapted to be moved in one direction by theA Y,

gases entering the cylinders through one of the said ports and beingA a'daptedal'so to be Y Y v almost instantly' lretarded in :its movement 1. An` automatic fire arm comprising aV by the'gases subsequently admitted through theV other port, said vportsbeing'of'such relative sizejthat the vplunger` r retardingv gases are admitted vrinto the. cylinderV havingv substantially the samelpressureas the plunger f .moving gases.

JOSEPH DESTRE.

Ik aiix' my signature; 

